Migrate WebGL contexts on backgrounded tabs to the integrated GPU.

third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp

 /*
  * Copyright (c) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 181 matching lines @@
 WebGraphicsContext3DProvider* DrawingBuffer::contextProvider() {
   return m_contextProvider->contextProvider();
 }
 
 void DrawingBuffer::setIsHidden(bool hidden) {
   if (m_isHidden == hidden)
     return;
   m_isHidden = hidden;
   if (m_isHidden)
     m_recycledColorBufferQueue.clear();
+  m_gl->PerformanceHintCHROMIUM(hidden ? GL_LOW_POWER_CHROMIUM
+                                       : GL_DEFAULT_POWER_CHROMIUM);
+  m_gl->Flush();
 }
 
 void DrawingBuffer::setFilterQuality(SkFilterQuality filterQuality) {
   if (m_filterQuality != filterQuality) {
     m_filterQuality = filterQuality;
     if (m_layer)
       m_layer->setNearestNeighbor(filterQuality == kNone_SkFilterQuality);
   }
 }
 
@@ skipping 1054 matching lines @@
   if (m_pixelUnpackBufferBindingDirty)
     client->DrawingBufferClientRestorePixelUnpackBufferBinding();
 }
 
 bool DrawingBuffer::shouldUseChromiumImage() {
   return RuntimeEnabledFeatures::webGLImageChromiumEnabled() &&
          m_chromiumImageUsage == AllowChromiumImage;
 }
 
 }  // namespace blink